Concept uses human wisdom, not computer algorithms

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NEW YORK — Here's how we tend to organize our digital photos: We stick them into a folder on our computer and label it "Hawaii trip," or whatever. Here's a new way: Forget folders or albums. Just "tag" the photos based on what's actually in each frame. Now, extrapolate this concept to the ideas, images, videos — and people — you meet or wish to find online. If they're properly tagged, they're far easier to find.

That's "tagging," and it's currently all the rage among the digerati.

Tagging has the potential to change how we keep track of and discover things digital — even whom we meet online. Several startups are banking their futures on it.

It could be our salvation as we attempt to sift through the growing clutter of data we're amassing on our hard drives and on that growing digital repository that is the Internet.

"People are awash in an overwhelming sea of stuff," said Joshua Schachter, founder of del.icio.us, a service for tag-enabled online bookmarks. "Our ability to produce content far outstrips the ability to sort and consume it."

And with the growing production of photos, sound and video clips — material not easily searchable — tags become ever more important.

Take photos. You may have an album for your beach trip, another for a son's birthday party. But how do you find photos of your wife?

Before, you had to scan through albums one at a time. With tags, you simply label photos individually when you first store them — with descriptive words such as "birthday," "vacation," "fall 2004" and with the names of the people in each picture. You can then search for your wife's tag.

Flickr, which Yahoo Inc. bought in March, takes that approach — and more. Your friends can tag your photos, too. So while you might have neglected to tag your friend's daughter, your friend can do so.

"Tags enable you to slice through all the photographs that you've got in whatever way you want to find them," said Caterina Fake, Flickr's co-founder.

At del.icio.us, as in "tastes good," people tag and share Web links. Keepers of Web journals tag their entries to make them easier to find through a blog search engine called Technorati. Consumating.com lets you — and others — tag your dating profile.

Though many Web sites have long embedded search keywords, or metadata, tagging has a social component that gives it its power.

"Tagging is something selfishly useful. It helps you understand and categorize something for yourself," Technorati founder David Sifry said. "But I can take advantage of the fact that you and hundreds and thousands of people have also tagged the things" for themselves.

Human helpTagging is fundamentally about tapping the collective human wisdom, rather than relying on a computer algorithm, for search, said Ben Shneiderman, who teaches human-computer interaction at the University of Maryland.

And that human wisdom is bound to help you discover information a computer might not otherwise know to retrieve.

"I'm sure the author of this never imagined this was a lifehack, but a del.icio.us user decided this falls into that tag," Brier said.

Brian Dear adopted tagging for EVDB, an events listing service he launched a month ago, so people can find things they might never know to seek. View a listing, and you see a list of tags it uses. Click on one to get events just like it.

"You start being able to have other people discover things for you without you knowing you wanted to look for them," said Clay Shirky, professor at New York University's Interactive Telecommunications Program.

Tagging saves labor costs, too. Dear would otherwise have to pay a whole staff to categorize and annotate listings.

Group taggersEntire communities have formed around tagging.

Nearly 2,000 Flickr users are part of a "squared circle" group, all sharing a desire to crop into squares photographs of circular objects.

Other users tag satellite images of their childhood neighborhood "memorymaps" and annotate them with stories about growing up.

At 43 Things, where visitors list their goals, those inspired by the book "Getting Things Done" have tagged their goals "GTD." The tag helps users find what like-minded people want to accomplish and perhaps adopt those goals, too.

Conference-goers are frequent taggers.

Organizers of a blogging conference in Paris last week encouraged participants to tag their entries "lesblogs." Italian blogger Luca Lizzeri did just that and got hundreds of additional visitors.

Sites like Technorati not only let you search its own indexes, but also pull items from other sites. So a search for "tsunami" brings together Flickr photos and del.icio.us links besides blog entries — creating a mini-magazine of sorts on the fly.

Unlike hierarchical classification systems, taggers create categories spontaneously. There are no rules to craft on what categories to include and what falls under each.

Hierarchies "are more accurate, but they move less quickly," said David Galbraith, founder of a tag-based wish list called Wists. "It takes a long time for people to sit down and agree on them."

Matthew Haughey, founder of the community blog MetaFilter, considered a taxonomy to organize archival posts but "it's hard to make perfect categories and sub-subcategories." If you wanted to paint a fence, should you look under "home and garden" or "household"?

The blogging site LiveJournal plans to introduce tags in the next few months as an alternative to categories, and Rojo Networks Inc. launched a service last month for tagging news stories, so no longer are you limited to sorting items by publisher.

Of course, tagging has its drawbacks, and some Webophiles aren't quite convinced it will evolve into the Next Big Thing.

Consider classifications for a common pet.

"If one group decides we're going to call them `canine,' another `dog,' another `puppies,' ... when someone goes to search for what they call the dog, they are not going to pick up everybody's tagged instances," said Geneva Henry, executive director of the Digital Library Initiative at Rice University.

Engineers recognize the shortcomings and are working on better tools.

Search for "automobiles" of Flickr, and you're given "cars," "car" and "porsche" as related options. Enough people tag photos both "automobiles" and "cars" that clustering software can tell they are related.

Another drawback lacks an easy solution, though. Once tagging takes off, marketers are bound to add irrelevant tags to hijack you to the latest Viagra ad.

Warns Danny Sullivan, editor of the online newsletter Search Engine Watch: "The noise and deliberate manipulation will probably just bring the system into a crashing halt."